The Wall Street Journal compares presidential dimensions in a graphic earlier this monthThe Washington Post revisits the timeworn but always entertaining Presidential Height Index, according to which the tallest candidate for US president has won on almost every occasion over the last century or so -- especially if you count Al Gore in 2000, cruelly denied the office thanks to some short Supreme Court judges. So far, the minuscule size of John McCain, who under some conditions cannot actually be seen at all without the aid of an electron microscope, hasn't been a major problem, since he's mostly been standing on the podium alone. But as the blogger Saccharinist notes, that's about to change: at the post-convention presidential debates, the 6'1" Obama will tower over him. As might his vice-president, depending on who he picks -- and that could spell trouble:

When Dukakis chose the 6'1" (1.85m) Lloyd Bentsen as his running mate for the 1988 presidential campaign against 6'2"" (1.88m) George Bush the elder, it seemed like a good idea at the time -- an undoubtedly concerted effort to present a more balanced height average for the Democratic ticket. Sadly for Dukakis, none of his advisers succeeded (if they even tried) in predicting just how unfortunately silly a presidential candidate looks when his lesser-office partner towers above him.

Generally speaking, pundits and political thinkers laugh off theories like the Presidential Height Index. They shouldn't. Gut reactions to the impression that a candidate makes, along with many other completely unexpected factors, are exactly what determines election outcomes. And research has already established that taller men are more likely to marry and have children...